One of the most fundamental rules governing small unmanned aircraft system (sUAS) operations under 14 CFR Part 107 is the requirement to fly during specific times of day. Unlike manned aircraft, which have well-established night VFR procedures, small drones present unique visibility and collision-avoidance challenges that led the FAA to restrict routine operations to daylight hours — with a carefully defined exception for civil twilight. Whether you are preparing for the Part 107 knowledge test or simply want to operate legally, mastering these time-of-day rules is non-negotiable.
This article explains exactly when you are permitted to fly, what civil twilight means and why it matters, what equipment is required when you push into those pre-dawn or post-sunset windows, and how the rules now accommodate true night flight. Every concept here is drawn directly from 14 CFR Part 107 and the FAA's official guidance.
The Core Daylight Requirement
Under 14 CFR §107.29, a remote pilot in command must operate an sUAS only during daylight or within the period of civil twilight, or at night if the requirements of §107.29 are met. Daylight is straightforward: it is the period between official sunrise and official sunset at the operating location. These times are published in the Aeronautical Information Manual (AIM) and are readily available in aviation weather apps, the FAA's B4UFLY app, and other planning tools. The key word is official — this is the published astronomical time for your specific geographic location, not when the sky first begins to brighten.
It is important to note that sunrise and sunset times vary by location and by date. A remote pilot operating in a mountainous region, for example, may experience local terrain blocking the sun well before official sunset, but the legal definition still references the published time, not the actual physical horizon at that spot. Always use the published local time for your operating area.
Civil Twilight: The Extended Window
Civil twilight is the period that occurs 30 minutes before official sunrise and 30 minutes after official sunset. During civil twilight, enough ambient light remains (or arrives) in the sky that ground-level objects are generally distinguishable without artificial lighting. This is why the FAA determined that sUAS operations can reasonably continue during this window — provided an important equipment condition is met.
Civil twilight should not be confused with nautical twilight or astronomical twilight, which extend further beyond sunset or before sunrise but involve significantly darker conditions. Only civil twilight is addressed in §107.29 as a distinct daylight-adjacent window; operations beyond civil twilight are addressed separately as night operations, discussed below.
To calculate civil twilight for any given day and location, you subtract 30 minutes from the published sunrise time to find the beginning of morning civil twilight, and you add 30 minutes to the published sunset time to find the end of evening civil twilight. For example, if sunset is published at 7:42 PM local time, you may continue sUAS operations — with proper lighting — until 8:12 PM local time.
Anti-Collision Lighting: The Essential Equipment Requirement
Operating during civil twilight is not simply a matter of staying within those 30-minute windows. The regulation requires that the sUAS be equipped with anti-collision lighting that is visible for at least 3 statute miles. This lighting must be active and operational any time you fly during civil twilight or at night. The purpose is to make the drone conspicuous to manned aircraft pilots and other observers who might otherwise not see the small, dark aircraft against a low-light sky.
The FAA does not specify the exact color of the anti-collision light in §107.29, but it must meet the 3-statute-mile visibility standard. Many commercially available drones come equipped with LED strobes that satisfy this requirement, but it is the remote pilot's responsibility — as part of the pre-flight inspection — to confirm the lighting system is functioning before taking off during civil twilight or at night. A light that is dim, flickering, or not visible at distance does not comply with the rule.
It is also worth emphasizing that anti-collision lighting during civil twilight or night operations is not optional. If your lighting system fails after you are already airborne and civil twilight begins (or continues into night), you should land as soon as safely practicable. Continuing to fly without functioning lighting during civil twilight or at night is a regulatory violation.
Night Operations
Prior to a 2021 rule change, night operations were entirely prohibited unless a remote pilot held a specific FAA waiver. The FAA's 2020 Remote ID and Operations Over People final rule — which took effect in April 2021 — amended §107.29 to permit routine night operations, not just civil twilight, as a standard rule-based permission rather than requiring a waiver. To operate at night, the remote pilot must have completed the updated recurrent training or testing requirements covering night operations, and the sUAS must be equipped with anti-collision lighting visible for at least 3 statute miles, active during the entire flight. Because night operations are now authorized directly by §107.29, a waiver is no longer required for night flight itself.
Remote pilots should still ensure they are operating in accordance with any other applicable airspace authorizations, operating limitations, and the specific anti-collision lighting and training requirements spelled out in §107.29, since these are the conditions that make night flight legal without a waiver.
Why These Rules Matter
The daylight, twilight, and night rules exist primarily to support the see-and-avoid principle that underlies all aviation safety. Manned aircraft pilots rely heavily on visual scanning to detect traffic. An sUAS that is small and dark and operating without lighting in low-light conditions presents a genuine collision hazard, particularly near airports and in airspace shared with helicopters, agricultural aircraft, and other low-flying planes. Anti-collision lighting reduces this risk by making the drone visible during the portions of the day when ambient light is insufficient to reveal a small aircraft at typical separation distances.
From a practical standpoint, operating at the limits of daylight also degrades the remote pilot's ability to maintain visual line of sight (VLOS), which is its own separate requirement under §107.31. Even if the legal time window allows flight, poor visibility at dusk or dawn can make it impossible to determine the drone's orientation, altitude, and trajectory — increasing the risk of loss of control or airspace incursion.
Key Numbers and Rules
- Daylight operations: Permitted between official sunrise and official sunset at the operating location.
- Civil twilight window: Begins 30 minutes before official sunrise; ends 30 minutes after official sunset.
- Anti-collision lighting requirement: Required during civil twilight and at night; must be visible for at least 3 statute miles.
- Night operations: Permitted under §107.29 without a waiver, provided the remote pilot has completed updated training/testing and the sUAS has compliant anti-collision lighting.
- Regulatory reference: 14 CFR §107.29 governs daylight, twilight, and night operations.
- Pre-flight check: Confirm anti-collision lighting is functional before any civil twilight or night operation.
Common Test Traps
- Confusing civil twilight with nautical twilight: The FAA specifically references civil twilight (30 minutes before/after sunrise/sunset). Nautical twilight extends further and is not separately defined for Part 107 purposes.
- Thinking anti-collision lighting is optional during civil twilight or night: It is not optional — it is a hard regulatory requirement any time you operate during the civil twilight window or at night, period.
- Forgetting the 3-statute-mile visibility standard: The test may ask about the specific distance requirement for anti-collision lighting. The answer is 3 statute miles.
- Assuming civil twilight always equals 30 minutes of usable light: The rule grants the window, but actual visual conditions during civil twilight vary by weather, terrain, and season. The regulatory window does not guarantee safe VLOS.
- Believing a waiver is still required for night flight: Since the 2021 rule change, night operations are authorized directly under §107.29 with proper training and anti-collision lighting — no waiver is needed for night flight itself.
- Mixing up local time vs. Zulu time: Sunrise and sunset times used for Part 107 planning should be in local time for the operating location, though the FAA publishes times in various formats. Always confirm you are using the correct local time zone, including accounting for daylight saving time where applicable.